In​ Marissa's calculus​ course, attendance counts for 10​% of the​ grade, quizzes count for 20​% of the​ grade, exams count for 55​% of the​ grade, and the final exam counts for 15% of the grade. Marissa had a 100% average for​ attendance, 89​% for​ quizzes, 82% for​ exams, and 81% on the final. Determine​ Marissa's course average.

2 answers

.10*100 + .20*89 + .55*82 + .15*81 ≈ 85
I would do it this way:

1.0(.1) + .89(.2) + (.82)(.55) + .81(.15)
= .8505

or 85%